Rent Shop Volunteer Join

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Sunday - May 02, 2010

From: Austin, TX
Region: Southwest
Topic: Compost and Mulch, Planting, Soils, Trees
Title: Use of fresh clippings from tree trimmers for mulch in Austin
Answered by: Barbara Medford

QUESTION:

Hi, The tree trimmers are in my neighborhood (east central Austin) to clear the power lines and said I can have a load of free mulch. I am wondering if there is any harm in using the fresh mulch from our neighborhood trees in my flower beds and around our native trees. In particular, how likely is it that something in the mulch could harm my plants or big pecan trees (should I be worried about diseases or harmful/invasive seeds)? Also, we have been organic since we moved here 2 yrs ago -should I worry that local trees might have been sprayed with something nasty this spring that would end up in the mulch? Thanks!

ANSWER:

We once had a sweetgum stump ground out of a flower bed in our garden, and the plants, including roses, planted there after that were profuse and vigorous. The soil was soft and loose, and had all that good organic matter in it. On the other hand, this was our own tree, on our own property, and we watched the grinding being done. We knew about herbicide use (we didn't use it), diseases (there weren't any in the old tree) and had only cut it down because of the invasive roots of Liquidambar styraciflua (sweetgum). So, while we had a good experience, your points about the condition of the clippings are well taken. 

Our preference would be to compost the whole stack of stuff, adding nitrogen in the form of manure, cottonseed meal, or fresh green material. That would be a big project, taking a lot of space, and probably about two years, but it would remove most of the objections having to do with pesticides or diseases, as a hot enough compost pile will take care of about anything. However, you might be able to compost it in place, as it were, as long as you were conscious that the decomposition of the wood chip material would be taking away nutrients from the soil itself. Adding nitrogen-rich material to the top layer as the lower layer decomposed away would probably alleviate that. Whether something that coarsely ground would be acceptable in flower beds, we couldn't say, but you certainly couldn't put it on when you were expecting seedlings to come up, or plants that were cut back in the Fall to re-emerge, they would be smothered. 

Read this article from North Carolina University Mulching Trees and Shrubs, from which we extracted this paragraph:

"Properly composted wood chips can be used as a long lasting mulch that weathers to a silver-gray color. Unfortunately, most wood chip material is sold as a fresh material rather than as a composted or aged material. The chips decompose slowly, but as they decompose, microoorganisms use nutrients from the soil that might otherwise be available for plant growth."

 

More Compost and Mulch Questions

Native plants for screen in Colleyville TX
March 12, 2009 - My soil is pure sand that goes down as far as I can dig. I am needing native plants to use as a screen, that grow to be 6-10 ft. tall. Also, since my plantings dry out so quickly, would it be helpfu...
view the full question and answer

Stubs of Texas Star Hibiscus in Abilene, TX
March 26, 2009 - We have cut back our outdoor Texas Star Hibiscus for 4 years and now have a large number of old stubs that the new growth must navigate around. Will it kill the plant if we dig up the old stubs? At so...
view the full question and answer

Instructions for composting in southeast Texas
February 18, 2008 - Do you ever offer composting classes? I live in Houston and would like to start composting in my backyard... are there any particular books you would recommend for composting in SE TX? Thank you!
view the full question and answer

Source for pecan mulch used at Wildflower Center from Austin
November 11, 2011 - Hello Mr. Smarty Pants I was recently at the Wildflower Center. I saw all the pecan shell mulch and was wondering where you get it from. I noticed awhile back that it is one of the recommended mu...
view the full question and answer

Leaf browning on blackfoot daisy in Arizona
August 26, 2008 - Blackfoot daisy plant was doing great; then, in one day, it turned brown like it had no water. Have a watering system in place which waters once a day for one hour 1/2 gallon a hour.
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.